Evolutions in the Elastic Constants of Ca-Montmorillonites with H2O/CO2 Mixture under Supercritical Carbon Dioxide Conditions

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• 作者：Wei N. Zhang ; Hai X. Hu ; Xiao C. LiZhi M. Fang
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：February 9, 2017
• 年：2017
• 卷：121
• 期：5
• 页码：2702-2710
• 全文大小：769K
• ISSN：1932-7455

文摘

Clay mineral plays a crucial role in determining permeability and affecting mechanical properties of caprock formations in geologic carbon sequestration (GCS) and enhanced oil recovery (EOR) engineering. In the corresponding environment, CO₂–H₂O intercalation not only causes swelling or shrinkage of clay mineral but also results in affecting mechanical properties of mineral. However, influence of quantitative CO₂/H₂O adsorption on mechanical properties of clay still remains unknown. This work investigated evolutions of elastic properties of Ca-MMT with variable CO₂–H₂O component using molecular dynamic method. Elastic coefficients C_ij, bulk modulus K, shear modulus G, Young’s modulus E_ii, and Poisson’s ratio E_ij were correlated to qualified adsorption of CO₂–H₂O mixture. We obtained the following conclusions: (1) in-plane elastic constants, bulk modulus, shear modulus, and Young’s modulus E₃₃ had distinct correlation with the profile of d₀₀₁ spacing as a function of H₂O content at fixed CO₂ content; (2) no distinct evolution profile was found in Poisson’s ratio as a function of CO₂ or H₂O content; (3) we revealed that the mixture of CO₂/H₂O caused decrease in strength of clay mineral; and (4) varying ranges of all elastic constant were summarized for clay-CO₂–H₂O considered in this work.